A seasonal study of the decomposition pattern and insects on submerged rabbit carcases

Abstract

ABSTRACT There is a long history of using insects on a decomposing corpse as an invaluable tool to estimate the minimum post-mortem interval (PMI) during death investigations. The present study was carried out to study the decomposition pattern and insects associated with a submerged rabbit (Oryctolagus cuniculus Linnaeus, 1758) carcase. A total of 1795 insect specimens were found to be associated with different decomposition stages. During the submerged fresh stage three species from the genus Chironomus visited the carcase. During the early floating and floating decay stages, insects belonging to Coenagrionidae, Chironomidae, Lestidae, Aeshnidae families along with the aquatic beetles i.e. Enochrus esuriens (Walker, 1858), Regimbartia attenuata (Fabricius, 1801), genus Helochares and Canthydrus laetabilis (Walker, 1858) visited and colonised the carcase. The advanced floating decay and sunken remains stage saw a prominence of Ranatra digitata (Hafiz and Pradhan, 1949), Ranatra filiformis (Fabricius, 1790) and genera Hydroglyphus, Hypoporus, Laccophilus, Berosus and Helochares. The Post-Mortem Submersion Interval (PMSI) was found to be longest in the winters (44 days, ADD = 1066.5) and shortest in the rainy season (16 days, ADD = 405.5) while the spring and the summer season showed a moderate PMSI of 26 days (ADD = 632.5) and 19 days (ADD = 472.5) respectively.